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    <script>
     
        // 数组去重 用set
        let arr = [1,2,3,4,1,1,1,1,2,2,2];
        let n = new Set(arr);

        //特点 1. set没有重复的值
        console.log(arr); //[1, 2, 3, 4]
        console.log(n); //Set(4) {1, 2, 3, 4}

    </script>
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